SU1418565A1 - Device for measuring diameters of parts - Google Patents

Abstract

The invention relates to a measurement technique and can be used in process control in the process of manufacturing parts, for example, on lathes. The purpose of the invention is to show the accuracy of measurements by eliminating the error in measuring the angle between the beams. The beam of radiation of the laser source 1 through a mirror 3 performs a circular scan and passes through the slit 7 of the light guide 4, the part 15 crosses the light guide curved along an arc of a circle. with

Description

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the diameter of which is equal to the distance between the scanning center and the end 16 of the optical fiber 4. The scanning center, the center of the circle and the end 16 of the optical fiber 4 are located on the same straight line. ; Signal from photodetectors 5.6 at the input; amplifier 9 has a constant value during the entire time of illumination of the slit 7. The information processing unit determines the value corresponding to the unlit illuminated part of the light guide and outputs the value of the diameter of the measured part with a uniform error in the entire measurement range . 2 Il.

The invention relates to a measuring technique and can be used in process control in the process of manufacturing parts, for example, on lathes. The purpose of the invention is to improve the measurement accuracy by eliminating the I determination error between the rays I. In FIG. 1 shows in principle the diagram of the device in FIG. 2 - I measurement scheme.

The device contains a laser radiation source 1, a scanning system of a circular sweep of the beam, made in the form of a mirror 2 rotated by a drive 2, a light guide 4 with photodetectors 5 and 6.

The light guide 4 is a cylindrical curved rod from an optical center; La with a mirror reflecting coating applied on its surface. 1A transparent window (slit) 7 is made along the generator rod in the mirror coating. Photo detectors 5 and 6 are connected to information processing unit 8 containing amplifier 9, which is connected to pulse generator 11 connected in series with control unit 10 associated with the computing unit 13 connected to the indicator. 14 The measuring part 15 is located between the mirror 3 and the light guide 4. The mirror 3 is mounted so that the axis 0 of the part 15 is perpendicular to the scanning plane. The distance 00, from the axis of rotation of the mirror 3 to the axis of the part is greater than the maximum radius of the measured part. The slit 7 of the light guide 4 is a portion of an explosive arc of a circle (Fig. 2).

Scan center, center of the circle and center of one of the ends 16

The light guide 4 is located on the same straight line, the diameter of the circle along which the light guide 4 is bent is equal to the distance between the scanning center and the end 16 of the light guide 4.

The device works as follows.

A beam of radiation from a laser source 1, arriving at a mirror 3 rotating by means of an actuator 2, scans the slit 7 of the light guide 4, crossing the part 15. A signal corresponding to the time from the beginning of illumination of the slit 7 of the light guide is formed.

4 until the moment of interruption of the illumination when the beam touches the part 15.

When the beam moves along the slit, the illumination of each of the photodetectors 5 and 6 is not the same at different points in time, but due to the sequential switching on of the photoreceivers 5 and 6. The total signal at the input of amplifier 9 has a constant value throughout the entire time of illumination of the fiber slot.

Photodetector Illumination Signal

5 and 6 is applied to the control unit 10 of the pulse generator 11 and turns it on. A pulse generator 11 transmits a certain number of pulses n corresponding to the entire illumination time of the photodiodes. When the part of the light beam overlaps, the pulse generator is turned off.

In information processing block 8, the constant N - is permanently stored. the number of pulses corresponding to the full illumination of the fiber. Computing unit 13 determines the value

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The n corresponding to the non-illuminated part of the light (segment Vng) calculates the diameter and gives the value of the diameter of the measured part to indicator 14.

The circuit in FIG. 2, it follows that in this device the measurement is reduced to fixing a point B corresponding to the interruption of the beam at the moment the part touches the point of contact A and a circle lying on the arc, whose diameter is equal to the distance from point B to the axis O of the turn of the beam. The distance BB is measured, and the size of this segment is judged on the diameter of the measured part.

Due to the fact that the receivers in the device are located at the ends of a fiber bent along an arc of a circle whose diameter is equal to the distance between the scanning center and one of the ends of the fiber, a uniform error is ensured over the entire measurement range.

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Claims (1)

Invention Formula A device for measuring the diameters of parts, comprising a sequentially installed laser radiation source, a scanning circular scan system, photodetectors located on the side of the monitored part opposite to the scanning system, and an information processing unit connected to the photodetectors that increase the accuracy of measurements, it is equipped with a light guide with transparent oKHolM, made along the entire length of the forming surface of the optical fiber curved along the arc of a circle and so that the transparent window is aligned with the scanning plane, the scanning center, the center of the circle and one of the ends of the fiber are located on one straight line, the diameter of the circle along which the fiber is bent is equal to the distance between the center of scanning and this end of the receiver, and the photodetectors are located in the ends of the fiber. five 0 five at; FIG. 2